/**
 * @author : zzr
 * @description :
 * @date :
 */
public class Test {
    public static String func1(String str) {
        int n = str.length();
        String string = "";
        for (int i = 0; i < n; i++) {
            char c = str.charAt(i);
            if (!string.contains(c + "")) {
                string += c;
            }
        }
        return string;
    }
}
